8.10 SEQUESTRATION

Description

The MidCoast region of NSW has high potential for carbon sequestration through its extensive vegetation cover and coastal wetlands. The total area of the MidCoast is just over 1,000,000 hectares (ha), which includes:

• 23,266 ha of coastal wetlands (2% of the LGA), and • 635,651 ha vegetation cover (63% of the LGA).

Increased coverage and management/restoration of vegetation and wetlands provides an opportunity for increased carbon sequestration in the region.

Wetlands

The MidCoast is home to 23,266 ha of coastal wetlands. Council has acquired and remediated around 5,160 ha of coastal wetlands to date, and is working to increase this to more than 6,000 ha in the near future.

Coastal wetlands are generally known to be 10 times more effective at sequestering carbon than other forest vegetation types 38 . Seagrass beds, mangroves and saltmarshes store large amounts of carbon. They draw in carbon as they grow, and much of this is later transferred into the rich organic soils held by their roots. That carbon can remain in the soil for thousands of years, making wetland protection, management, and restoration important long-term natural climate solutions.

Recent research published in Geophysical Research Letters39 reports on studies of two hydrologically restored freshwater coastal acid sulfate soil (CASS) wetlands located in MidCoast at Cattai and at Darawakh wetlands and restored by MidCoast Council. This reports organic carbon accumulation rates of, on average 0.24 kg per square metre per year. Extrapolated on a simple basis to the whole LGA, this suggests the following approximate sequestration rates:

• 200,000 tonnes of CO2 per year across all wetlands in MidCoast, • 45,000 tonnes of CO2 per year in wetlands already restored by Council, • 7,500 tonnes of CO2 per year in wetlands Council is set to acquire and remediate in coming years

Considering emissions by Council’s operations and waste, and by the MidCoast community as a whole, ’blue carbon’ sequestration through restoration of the region’s coastal wetlands is a potentially significant part of any strategy for achieving net zero emissions in line with science.

38 https://climatechange.lta.org/wetlands/ 39 Brown, D. R., Johnston, S. G., Santos, I. R., Holloway, C. J., and Sanders, C. J. (2019). Significant organic carbon accumulation in two coastal acid sulfate soil wetlands. Geophysical Research Letters, 46, 3245–3251. https://doi.org/10.1029/2019GL082076

In addition, considering that degraded wetlands can actually release significant quantities of carbon back into the atmosphere, restoration of wetlands may actually deliver even more significant carbon sequestration than the figures above.

Vegetation

Council efforts to manage and enhance tree canopy cover and green spaces across the MidCoast, and to manage the region’s natural heritage are set out in:

• MidCoast Council’s (draft) Vegetation Magement Policy and Greening

Strategy40, and • MidCoast (draft) Biodiversity Framework 2020-203041

Initiatives set out in these documents, and other actions and plans by Council include:

• The draft Biodiversity Framework 2020-2030 includes initiatives related to partnering with private landholders to protect and enhance vegetation including the Land for Wildlife Program.

• The draft Greening Strategy includes tree planting initiatives on public and private land including increasing the capacity of Council’s nursery to supply local native plants. During 2019/20 approximately 18,000 plants were propagated and planted in the region.

• A Tree Preservation Order (TPO) to minimise and regulate the removal of native vegetation in urban areas currently only applies to parts of the former

Great Lakes LGA. Council’s draft Vegetation Management Policy is proposing to replace the current TPO with a broader, more targeted approach that will apply to the entire MidCoast LGA and aim to protect native vegetation that has significant ecological value or contributes to the scenic amenity or character of an area.

• Council has an Offsetting Procedure which provides a framework for the planting of trees on public land to replace trees lost through Council’s infrastructure improvement projects. This procedure results in more trees, since the trees removed are replaced at higher ratios, i.e. at 2:1; 4:1 and 10:1 ratios depending on their conservation status. This is also generally applied to private developments through Council’s Development

Application process, but a formal policy has not yet been adopted. Since this procedure was introduced in 2018 around 10,000 plants have been or are proposed to be planted to offset tree losses.

• Significant tree planting for biodiversity purposes will also be undertaken during 2021 and 2022 in conjunction with a number of bushfire recovery

40 https://haveyoursay.midcoast.nsw.gov.au/greening-strategy-and-vegetation-management-midcoast/draftmidcoast-greening-strategy 41 https://haveyoursay.midcoast.nsw.gov.au/biodiversity-framework

grants Council has received under Federal and State Governments’ funding programs.

Carbon sequestration from increased vegetation will depend on the type and scale of new vegetation, and on the age of planted trees. A mature tree will typically sequester around 20 kg of CO2 annually, while young trees may sequester around one quarter to one third of this.

Further to these initiatives Council may seek to partner with third parties (e.g. notfor-profit organisations like Greenfleet) to develop and restore biodiverse forest areas within MidCoast, whether to directly offset Council’s emissions or to create carbon offsets in local afforestation that helps other organisations to reduce their carbon footprint.

Scope for abatement

Risks and mitigation

Costs and benefits

The scope for abatement is clearly significant both in the context of Council’s emissions from its operations, and for the region as a whole.

The net amount of carbon that will be sequestered as a direct result of Council’s initiatives, through its wetlands restoration program, Greening Strategy and Biodiversity Framework actions is not estimated. The development of a simple framework to estimate carbon sequestered from Council’s actions can be considered as part of the ongoing implementation of the Climate Change Strategy.

Risks and mitigation strategies for wetlands restoration and vegetation management would be addressed within Council’s strategies, programs and projects related to these activities.

Costs and benefits of wetlands restoration and vegetation management would be addressed within Council’s strategies, programs and projects related to these activities.